Float trowel for cement floor finishers



Dec. 15, 1953 M,E.'wH1TEMAN FLOAT TROWEL FOR CEMENT FLOOR FINISHERS Filed April 12, 1948 AlvlA/f/ JN VEN TOR. 1 Myer/ME.' Mac/wg i l BY Paiented Dec. l5, 1953 UNITED stares estasi EFECE FLOAT TROWEL FOR CEMENT FLOOR FINISHEES This invention relates to a neat trowel iol' cement door nishers and may be regarded as an improvement over a construction disclosed in my prior U. S. Letters Patent No. 2,193,929, issued April 30, 1940.

In the above numbered patent there is disclosed a cement floor finisher wherein three radially eX- tending nish trowels are rotatably mounted about a vertical central axis and are adapted to be driven by a suitable source of power. A handle is secured to the device to facilitate its being manipulated over the surface of a cement door that is to be finished and by means of an adjustment the tilt of the trowels can be adjusted while they are being rotated about the vertical central axis .so as to cause them to impart the desired finish surface to the concrete.

Preparatory to Finishing a cement or concrete door it is desirable to perform a so-cailed iioating operation wherein a relatively broad trowel is worked in a iiat condition over the wet cement to prepare the cement for the iinishing operation. In the course of this iioating operation the fines are effectively worked to the surface and the cement is otherwise advantageously prepared for the nishing operation.

While the nish trowes disclosed in the above mentioned patent are capable of assuming or untilted positions with relation to the cement floor, they are generally unsuitable iol pericrlnfi' ing the iioating operation due to the fact that they are relatively narrow and their are seldom if ever turned upwardly. Consequently if the finish troweis were for the floating operation there would be always a tendn o ency for the tro-weis to dig into the wet cement in the course oi their rotation about the vertical central axis.

An object of the present invention is to vide a fioat trowel which may be ov e nnish trowels of a cement floor nisher the generalv type disclosed in the above numbered patent. In this manner, on applying the iicat trowels to the machine the finisher be easily and quickly converted to a iioating machine. The

trowels may be of adequate breadth and may have all of their side edges bent upwardly so to avoid digging into the wet cement white the trowel is rotated about the vertical cent-.al artis in a at position. iicated the float troweis can be easily and quick-- ly removed from the finish trowels thus converting the machine into a nishing machine and the nishing operation may then be periorniecA Another object of the invention is to provide to bars l 'l on the backs oi finish troweis After the cement been.

a cement floor finisher which is so constructed that it may be easily and quickly converted from a oating machine into a finishing machine, or vice versa.

A further object of the invention is to provide a float trowel that is applicable to the finish trowel of a cement floor iinisher which will remain in position when applied thereto but which can be easily and quickly removed.

With the foregoing and other objects in View, which will be made manifest in the following detailed description and specifically pointed out in the app-ended claims, reference is had to the accompanying drawings for an illustrative embodi ment of the invention wherein:

Figure 1 is a top plan View of a cement door finisher of the type disclosed in my prior patent but illustrating the oat trowels embodying the present invention as having been applied thereto;

Fig. 2 is a perspective view of one of the oat trowels embodying the present invention ina position wherein it is about tobe applied to one of the iinish trowels of the cement floor Finisher;

Fig. 3 is a vertical section taken substantially upon the line 3-3 upon Fig. 1; and

Fig. 4 is a sectional view taken sub-staniiallgr upon the line d-l upon Fig. 3.

Referring to the accompanying drawings wherein similar' reference characters designate similar parts throughout, the cement door iinisher illustrated in Fig. l is of the disclosed in my prior patent wherein there is a suitable source of power such as an electric motor l@ supplied with current through a cord and which is mounted on a box it. gear box serves to drive a vertical shaft, not shea/fn, which rotates a plate i3 on which a plurality of radially-extending equally spaced beai id. are mounted. rlhese bearings serve to rotatably support the inner ends of the bars i5 which tui-n are detachably secured such as by cap screws l Ou ter bars lil are also secured to the bars l'i provide recesses that pivotally receive pins 2S 4which are at equally spaced intervals on a ring 2i that is concentrically arranged around the plate i3. A handie 22 js secured to the gear boi; and assists at facilitating the n'ianipulation of the machine over the surface of the cement i'iooi to be iinished. A knob 23 that is mounted the handle serves on rotation to adjust a thrust collar on the vertical shaft which is en gageable with arms on the inner ends of the bars i5 that are disposed on the inner ends of the bearings ifi. Consequently, cy rotating the knob the inclinati-cn or tilt of the finish trowels I8 may be simultaneously adjusted while they are being rotated about the vertical central axis in the course of imparting a iinish surface to the cement iloor. The above described construction is the same and is disclosed in further detail in my prior patent referred to above.

While the iinish trowels may have their outer and inner ends bent upwardly slightly, as indicated at 25 and 2t, the side edges 2'! and 2S are not so bent. This is particularly true of the trailing edge 21 which imparts the smooth nish surface to the door as the trowels are moved there over. The linish trowels also are usually relatively narrow, as illustrated in Fig. 2, and be-` cause of their size and the lack of the upturnsd side edges the finish trowels are unsuitable for performing the iioating operation even. though the trowels may be adjusted by the knob 23 to assume perfectly horizontal positions.

The float trowel embodying the present invention consists oi a relatively broad section of sheet metal 2% which not only has its ends bent upwardly as indicated at 30 and 3i but also has the side edges bent upwardly as indicated at 32 and A cap 34 extends from end to end oi the oat trowel and may be spot Welded thereto as indicated at 35 adjacent the leading edge 32. This cap extends from adjacent the leading edge toward the trailing edge 33 so as to substantially cover over the forward half of the finish trowel when the neat trowel is applied thereto. The ends o the cap may be bent downwardly, as indicated at Se, over the upwardly bent ends 3B and 3i or the finish trowel. In this manner the cap 3d cooperates with the body of the float trowel to form a rearwardly open pocket designed to receive approximately the forward half of the finish trcwel. A spring clip 31 may be secured to the top oi the cap such as by spot welding and this spring clip is formedY with a detent 35i adapted to bev snapped over the bar il on the nnish trowel to retain the float trowel in position.

When float trowels constructed as above described have been applied to the nish trowels on the machine, the machine may be operated in very much the conventional manner except that the knob 2 3 is adjusted so that the nish trowels and consequently the float trowels theresi,

on will assume perfectly horizontal positions which are required in performing the iioating operation. As the float trowels have upwardly bent side edges, particularly the leading edge 32,

there is no tendency of the float trowels to dig into the wet cement in performing the iloating operation, Furthermore, as the float trowels have their pockets open rearwardly and are applied over the leading edge 28 of the finish trowels, there is very little danger or tendency for the float trowels to become displaced. from the iinish trowels. in' many instances the retaining spring clip 3l may be unnecessary due to the fact that the drag on the iioat trowels in the course of their movement tends to push the float trowels onto the finish trowels.

When the noa-ting operation is completed the spring clips 31 may be sprung upwardly to release the float trowels and they may be easily and quickly removed. This exposes the bottom surfaces of the finish trowels and the machine may then be used in the manner disclosed in my prior patent to perform the finishing operation in the usual manner.

From the above described construction it will be appreciated that by the use of the float trowels embodying the present invention a cement oor finisher may be easily converted into a floating machine and on removal of the float trowels the iinisher may be restored to a machine designed to perform the finishing operations on the cement.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims-w claim:

1. A float trowel for cement door finishers comprising a rectangular section of sheet metal having its edges bent upwardly, means providing a three-sided rearwardly open poolet on the back of the section adjacent the leading edge thereof adapted to partially receive a finish trowel of the finisher, and a spring clip secured to the top or the pocket-forming means and extending rearwardly therefrom so as to be engageable with the nnish trowel to retain the section thereon.

2. In combination with a cement floor finisher having one or more iinish trowels mounted for rotation thereon and adapted to be moved over a floor to be finished, corresponding ioat trowels underlying the finish trowels, said float trowels having rearwardly open pockets formed thereon adjacent the leading edges thereof partially rcceiving the finish trowels, and means on the iioat trowels for releasably retaining the float trowels on the finish trowels.

3. A neat trowel for cement door nnishers comprising a rectangular section of sheet metal having its leading edge and its side edges bent upwardl means providing upright surfaces on the upper side of said section arranged to engage the leading edge and end edges oi a finish trowel of a cement door iinisher so that said section can be held against lateral displacement with respect to the finish trowel by said surfaces, a rearwardly extending spring clip secured to said section extending rearwardly over the upper suriace of said section so as to 'ne' engageable with the nish trowel to retain said section thereon.

MARVIN EDWTN WHITEMAi-I.

References Cited in the ille oi this patent UNITED STATES' PATENTS 

